Stencyl has left me with a great 20-minute-ran-through-the-basic-tutorial impression. Stencyl has an astounding number of usable blocks and a custom code block for the things blocks just can't handle (although, I admit, I don't know how easy that is to use). I'm delighted to see that it even has Kongregate API blocks.<p>My general impression of block based programming tends to be that they've got a handful of blocks and a quickly-thrown together interface, but Stencyl certainly exceeds that with a number of integrated functions (such as a project "market" which makes downloading tutorials painless).